iio: proximity: vl53l0x: Fix return value check of wait_for_completion_timeout

iio: proximity: vl53l0x: Fix return value check of wait_for_completion_timeout

wait_for_completion_timeout() returns unsigned long not int.
It returns 0 if timed out, and positive if completed.
The check for <= 0 is ambiguous and should be == 0 here
indicating timeout which is the only error case.

Fixes: 3cef2e31b54b ("iio: proximity: vl53l0x: Add IRQ support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220412064210.10734-1-linmq006@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>